How long is the coax between the LP100 sensor and the K3? This can have a significant impedance transformation impact as you go to higher frequencies, leading to a different indicated SWR at each end.
73, Eric Stewart wrote: > Hi, > Now traffic on the new K3 Macro functions has somewhat died down, > I would like to raise again the issue of the K3's SWR measurement > accuracy. > > I did some tests using dummy loads and a LP-100 meter as follows. > > The dummy load is a precision 100W one which I measured with a VNA > and has a VSWR of <1.03 from 1 to 30 Mhz. To simulate a 2:1 VSWR > I used another dummy load (not quite as good) in parallel. > > The K3 output was from ANT1 using the internal ATU. The ATU was > automatically tuned to 1:1 on all bands. > The results I got for 2:1 VSWR are as follows:- > > LP-100 K3 > 160 1.99 1.8 > 80 1.99 1.8 > 60 1.99 1.8 > 40 1.95 1.8 > 30 1.97 1.6 > 20 1.97 1.4 > 17 1.97 1.3 > 15 1.96 1.2 > 12 1.96 1.5 > 10 1.96 1.4 > > As can be seen my K3 SWR indication consistently under reads. > However, it really gets bad on 20,17 & 15. > > From previous replies I understand that this under reading would > be compensated for in the firmware, sometime in the future . > > Is this still on the list of problems to be addressed ? > > 73 > Stewart G3RXQ > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
